Q: Which one of the following diluents is EAST suitable for reconstituting single-dose vials?
Explanation: Product inserts are the best sources of information concerning appropriate diluents for a given drug powder. However, BSWFI should not be used for reconstituting single- dose units because the preservative present would serve no useful purpose, and large amounts of the preservative could increase the incidence or severity of toxicity. The use of BSWFI may be appropriate if a powder in a multidose vial is being reconstituted.
Q: Polymyxin B sulfate is available in 10 mL parenteral vials labeled as containing 500,000 units. Which of the following statements is (are) accurate if the pharmacist wants to prepare 30 g of ointment (15,000 U/ g)? I. The pharmacist will use 9 mL of the polymyxin B sulfate solution. II. It will be best to incorporate the solution into an absorption base. III. The solution should be incorporated into 30 g of ointment base.
Explanation: x =9 mL of solution (C) 15,000 units/g x 30 g =450,000 units 15,000 U xmL 500,000 U 10mL To incorporate 9 mL of an aqueous solution into an ointment, water absorption bases such as Aquaphor or hydrophilic petrolatum zre suitable. The pharmacist would not incorporate 9 mL of antibiotic solution directly into 30 g of ointment base because the incorrect concentration of drug would result. Instead, 9 mL should be mixed with a total of 21 g of base.
Q: Alcohol is suitable as a solvent for menthol or salicylic acid when preparing which of the following dosage forms? I. lotions II. ointments III. Suppositories
Explanation: Because of the volatility of alcohol, it is not suitable in dosage forms from which it may slowly evaporate. If ingredients were dissolved in alcohol and incorporated into ei- ther ointments or suppositories, crystals of the ingredients would slowly appear on the surface of the dosage unit. However, one would expect alcohol to remain within the lotion formula until placed on the skin.
Q: How many mg of sodium chloride are needed to adjust the following solution to isotonicity if the pharmacist uses atropine sulfate powder and an isotonic solution of 2% cocaine HCl? [E values for atropine sulfate =.13; cocaine HCl =.16]
Explanation: The pharmacist will use 30 mL of the 2% cocaine HCl solution. Since this solution is already isotonic, it is necessary to render the 30-mL balance isotonic after calculating the contribution of the atropine sulfate toward isotonicity. Atropine sulfate 60 mL x1% = .6 g or 600 mg 600 mg xE value of .13 = 78 mg 30 mL x .9% NaCl = 270 mg (if only ingredient) 270 mg - 78 mg = 190 mg of NaClneeded